As one of exposure techniques for photographic light-sensitive materials, there is known a so-called scanner technique in which an original is scanned, and a silver halide photographic material is subjected to exposure based on resultant image signals to form a negative or positive image corresponding to the original image. The image-forming method utilizing the scanner technique is embodied in various recording apparatuses, and a semiconductor laser is employed as one of recording light sources for these scanner type recording apparatuses.
A semiconductor laser is small in size and available at a low price, and has facility in modulation and a long life. In addition, it has a further advantage that it may be worked with under a bright safelight because it emits a ray in the infrared region, resulting in improved facility for handling a photographic material.
A sensitive material to be used for such a semi-conductor laser is a photographic light-sensitive material having spectral sensitivity in the infrared region, and it can be obtained utilizing a spectral sensitization technique which consists of extending sensitivity toward a longer wavelength region by addition of a cyanine dye to silver halide photographic emulsions. Spectral sensitization for extension of sensitivity toward the infrared region is effected by using sensitizing dyes capable of absorbing light in the infrared region.
In recent years, as the scanning speed of a semiconductor scanner has been increased, a need for reduction of development processing time (within 15 seconds) has been felt.
However, with all conventional techniques, it frequently happens that a developer remains nonuniformly on a sensitive material when the sensitive material is squeezed out of a developing bath and transferred into a fixing bath in the course of the photographic processing, causing nonuniformity in the image which is called "development mark". This remains a grave problem.
As development time is shortened, it becomes necessary to accelerate the conveyance of the photographic light-sensitive material, as a result of which nonuniformity of development is more likely, and the occurrence of "development marks" increases.
Furthermore, conventional infrared-sensitive silver halide photographic materials used for the image formation utilizing semiconductor laser as a light source have a problem that they are insufficient in antistatic capacity and facility in travel of films.
Since a photographic material is generally constructed from electrically nonconductive support and photographic layers, it frequently happens during the production and upon the use thereof that electrostatic charges are accumulated by contact friction between surfaces of the same kind or different kinds of substances or by separation of superposed layers of substances of the same kind or different kinds through peeling. These accumulations of electrostatic charge cause many problems. More specifically, one serious problem consists in that light-sensitive emulsion layers are sensitive to the discharge of electrostatic charges discharged thereon before development processing to result in generation of dot-like spots, or branch-like or feather-like streaks on the developed photographic image. Further, secondary problems, such that a film surface on which electrostatic charges are accumulated is subject to adhesion of dust, causes poor condition of travel upon photographing and conveyance with a film-conveying device, make it impossible to effect uniform coating, and so on.
In the scanner method utilizing a semiconductor laser, it is essential to convey films at high speed and with exactness. As the film is conveyed at high speed, static electricity may develop, interfering with the smooth conveyance of the film, as a result of which it becomes impossible to obtain accurate images.
A problem similar to that described above is caused at the time of film conveyance (particularly before the dip in a developing bath) in an automatic developing machine designed so as to perform rapid processing.
One method for overcoming problems arising from static electricity consists in designing a photosensitive material with increase in electric conductivity of surfaces of the photosensitive material so that accumulated electrostatic charges may be dispersed and lost before discharge.
To this end, a wide variety of methods for increasing conductivities of a support and various sorts of layers coated at the surface of a photosensitive material have so far been thought out, and various hygroscopic substances and water-soluble inorganic salts, certain kinds of surface active agents, polymers and so on have been experimented with in order to improve conductivity.
For instance, it has been determined that photographic light-sensitive materials with excellent antistatic capacity and facility in smooth travel can be obtained by adding nonionic surface active agents to surface protecting layers.
In recent years, as discussed above, a development processing time (which has so far been above 20 seconds) has come to be in need of reduction. The soonest possible visualization of images has been keenly desired in the semiconductor laser-utilizing scanner method.
In particular, a great need has arisen for a system designed so as to perform the laser scanning and the development processing steps successively.
However, reduction of development processing time to a period not exceeding 15 seconds through addition of nonionic surface active agents as described above has turned out to be accompanied with a serious problem that nonuniformity of image quality, called "development mark", was caused. The development mark was thought to be ascribed to nonuniform progress of development corresponding to nonuniform distribution of a developer remaining on the surface of a photosensitive material after being squeezed out of a developing bath and transferred into a fixing bath, which is due to sporadic separation of developer from surface or separation of agent at the surface of the photosensitive material because of its very low solubility in the developer.
More specifically, the development caused by the developer remaining nonuniformly on the surface of the photosensitive material after the step of squeezing out the developer cannot be disregarded because as the developing speed is increased in order to shorten the development time, the occurrence of development marks is also increased.